The invention relates to a brake arrangement for motor vehicles with a brake lever supported by bearings for rotation about a pivot axis, an axially movable master cylinder piston and a compensator that transmits force between the lever and the master cylinder piston.
A brake lever and a two-stage master cylinder are known from DE-A-38 37 650. The master cylinder piston is loaded axially by a spring in the cylinder bore so that its end face protruding from the master cylinder housing is forced against the end of a free leg of the two-legged brake lever that is supported in bearings, free to rotate. When the brake lever is actuated the master cylinder piston is forced into the master cylinder housing against the force of the spring. The vector of the force transmitted from the end of the free leg to the end face of the master cylinder piston has an axial component as well as a radial component with respect to the master cylinder piston. As a result, the free end of the leg slides across the end face of the master cylinder piston each time the brakes are applied, the friction produced by this sliding this requires an increased force to be applied to the brake pedal.
In order to reduce the force on the brake pedal, the John Deere tractors in the 6000 series were equipped with a ball bearing between the brake pedal and master cylinder piston which, however, leads to higher manufacturing costs.
In the passenger car brake installation described in U.S. Pat. No. 4,404,803 a brake rod is used as a connecting link between the brake pedal and the master cylinder piston, which is connected in a joint to the brake pedal and whose free end is configured as a ball which engages a recess in the end face of the master cylinder piston with a pan-shaped bottom in such a way that the brake rod can tilt within a small angular range. This design is intended to avoid assembly tolerances between brake pedal and master cylinder piston and the positive locking force centralized on the master cylinder piston. However this design requires a relatively large amount of space, which is not always available, in particular, in agricultural, logging and construction machines.